Vascular and cardiothoracic surgeons use vascular grafts to repair or replace segments of arterial and venous blood vessels that are weakened, damaged, or obstructed due to trauma or disease such as aneurysm, atherosclerosis, and infection. Historically, vascular grafts have been either homografts, such as the patient's own saphenous vein or internal mammary artery, prosthetic grafts made of synthetic materials such as polyester (e.g., Dacron), expanded polytetrafluoroethylene (ePTFE), and other composite materials, or fresh or fixed biological tissue grafts.
However, synthetic grafts generally have inadequate patency rates for many uses, while the harvesting of homografts requires extensive surgery which is time-consuming, costly, and traumatic to the patient. Fixed tissue grafts do not allow for infiltration and colonization by the host cells, which is essential to remodeling and tissue maintenance. Consequently, fixed tissue grafts degrade with time and will eventually malfunction.
Due to the inadequacies of these currently available synthetic and biological grafts, and the high cost and limited supply of homografts, tissue engineered grafts are being developed which are sterilized, then seeded and cultured, in vitro, with cells. These tissue engineered grafts may be superior to other grafts for use in replacement therapy in that they may display the long term dimensional stability and patency of native arteries and vessels with normal physiologic functionality.
Historically, cell isolation and seeding in addition to culturing of tissue-engineered grafts generally requires the use of a sterile environment, such as a hood or specialized facility, such as an ISO Class 7 room. However, there are disadvantages to seeding and culturing tissue in such an environment. For example, these systems can be cumbersome for the user, inconvenient, time-consuming to use, and very expensive to build and maintain.
Thus, there exists a need in the art for compositions and methods that allow for the convenient, sterile isolation, collection and seeding of tissue engineered grafts and other prosthetic devices.